The present invention relates to a composition comprising a neonicotinoid-based compound having a high degree of insecticidal activity, a surfactant, and an organic solvent, which is capable of demonstrating stable effects and in which the types and amounts of surfactant and organic solvent are adjusted so as to prevent chemical damage in numerous types of trees. In addition, the present invention relates to a method for preventing damage to trees by harmful insects of numerous types or trees by injecting this composition into a tree trunk and allowing the chemical to circulate within the tree body.
